


In the dark

by orphan_account



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Anal Sex, M/M, Multiple Orgasms, Smut, a concussion is the only way to get ishigami senkuu to shut up, i wrote this for myself but i guess you can read it, its a cave and tsukasa does shit, maybe later idk put it where you want it to be its not like theres a lot of plot, non-con, set idk somewhere during the kingdom of science arc
Language: English
Status: Completed
Published: 2020-03-20
Updated: 2020-03-20
Packaged: 2021-02-28 20:49:11
Rating: Explicit
Warnings: Rape/Non-Con, Underage
Chapters: 1
Words: 2,692
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23223550
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: Senkuu goes to check out a cave that's supposed to house fruit bats, as a possible new source of miracle water... But instead of the bats, there's a man waiting for him.
Relationships: Ishigami Senkuu/Shishiou Tsukasa
Kudos: 297





	In the dark

**Author's Note:**

> i dont care im in isolation and im fucking writing tsukasenkuu
> 
> you saw the tags and the warnings, we are both adults, so like. thats on you.

Tsukasa held him down with his weight, cold moss pressed against Senkuu's cheek. His hands were up above his head, pinned with Tsukasa's arm, the man looming over his back. Senkuu held his breath, evaluating the situation. 

He was lying on the floor of a cave, too far from the village for anyone to hear him scream. This was the one with bats, Chrome had told him, so he came to check if it could be a possible source of nitrate... And Tsukasa was there, out of nowhere, bashing his head with a club. Were there any signs that he might appear? Nothing he could think of, as far as he knew, Tsukasa had no reason to be there. Or did he come to see the village for himself? Theories raced through his head, which was still being pressed into the ground by Tsukasa's large hand. Senkuu could barely feel his legs beneath his thighs, where his assaulter was sitting. 

"Senkuu..." Tsukasa's deep voice resounded in the cave. Senkuu froze, his head still pounding. "It's been a while."

"Sure has," Senku bit back. "Had I known you were coming, I'd have thrown a welcome party." 

Tsukasa chuckled.

"Of course you would," he said, and the grip on Senkuu's hands tightened. "The very fact that you could do it is somewhat problematic."

He leaned down, his lips nearly touching Senkuu's ear.

"Give me one reason not to slit your throat right now."

"How benevolent of you, to offer me a chance to bargain for my life," Senkuu snickered, trying his best to keep his breath steady. There was none. He couldn't think of a single reason Tsukasa would want him alive, he had none months ago when he broke Senkuu's neck, and he didn't have one now. What empty promise could he think of? How could he possibly side-step the man he had to die to once, just to get a chance to escape?

"I would only hope for you to be more honest this time," Tsukasa said, sounding somewhat dejected.

"Oh?" Senkuu chuckled, panic leaving him with no other idea but to be smug and try to bluff his way out when the chance appeared. "Did you feel betrayed when I stayed alive?"

"Not quite." Tsukasa let go of Senkuu's hands and yanked his head up by the hair. "Disappointed at first, I suppose. I did admire your ingenuity, though. I was certain I killed you."

"You did." Senkuu managed, his throat strained by his position. "I just have trouble staying put."

"You certainly do." Senkuu saw it now, in the corner of his eye, the stone knife Tsukasa reached for with his free hand. Its cold tip touched Senkuu's throat. "It's a shame to kill you again. It's going to be quick."

"What if," Senku started, stopping to swallow his saliva. "What if you used me instead?" He didn't see Tsukasa's expression, but he could tell that the suggestion surprised him.

"Senkuu," Tsukasa started, but Senkuu had no intention of letting him finish.

"Take me with you and I'll help you out. Nothing complicated, nothing beyond Egypt and Mesopotamia. Just a few inventions to make your work easier and food better. Then you can do what you want." 

Tsukasa laughed. A pure, honest laughter. "Are you that desperate to remain a scientist?"

Senkuu didn't reply and only grinned, hoping to have gained at least a little time. Even if he doesn't scream, someone should start looking for him if he's gone for too long. Kohaku would definitely realize something was off... Every second he could make Tsukasa waste was worth the effort. 

And then he could feel Tsukasa's weight lift off his thighs. It was almost exhilirating. Still, the man held Senkuu's hair in his fist, and yanked him up, nearly uprooting Senkuu's white mane. Now on his knees, Senkuu faced Tsukasa, who was standing tall over him.

"There's another way I'd like to use you though." He said, and immediately pulled at Senkuu's hair, throwing him against a wall and knocking air out of him. 

The world was shaking, spinning in Senkuu's eyes. A concussion? Minor one, if anything. Barely, he made out Tsukasa's frame moving around, then something rough being tied around his wrists. He was lifted by his collar, just to be thrown on the ground again, further from the cave exit. Then there was a cold, calloused hand holding his face up, and Tsukasa's eyes, completely unreadable. 

Though Senkuu's instincts told him what was about to happen.

He was still trying to stop his head from spinning when Tsukasa kissed him. With his lips now pliable, there was no resistance to Tsukasa's tongue, opening them up and ravaging his mouth. Another calloused hand tore Senkuu's robe open in one move. His breathing sped up as his mind was becoming more and more aware of the situation. The spinning didn't stop, but Senkuu was regaining control over his limbs. With what little strenght he had, he tried to pull away, tied up hands pushing at Tsukasa's chest. It was almost as if the man didn't notice the struggle. Tsukasa's lips pulled away after what felt like eternity, but Senkuu knew it couldn't have been more than twenty seconds. 

"Senkuu," With his eyes closed, Tsukasa leaned against him, their foreheads touching. "I missed you so much."

He then leaned down and bit Senkuu's neck. The pain steadied him up enough to scream. It felt like Tsukasa was actually trying to take a chunk out of him. When he let go, Senkuu could feel warm wetness dripping down from the wound. But Tsukasa didn't stop there. He went down to his shoulder, then the collarbone, then his nipples, sucking and biting wherever he pleased. This was not going to end anytime soon.

"Stop... it..." He managed through the pain. His brain felt like a lump of wet cotton, but it didn't stop the terror from filling him completely. This was not a thing he expected Tsukasa would do.

"Why should I?" Tsukasa muttered against Senkuu's ribs. His hand worked its way into Senkuu's underwear, working his semi-hard dick. 

_No._

He pulled Senkuu's underwear off with one swift move. Suddenly, his tongue was running the length of Senkuu's shaft. But before he had a chance to even register the pleasure, two fingers were pushed deep into his mouth, nearly making him gag. 

"For your own sake, you should leave as much saliva as you can on them." Tsukasa commanded.

He then applied his mouth in a much scarier, but a little better way, taking Senkuu in and sucking hard. Senkuu moaned, instinctively sucking on Tsukasa's fingers. Sure, it would be better for him to have something slick if Tsukasa intended on... fucking him properly, but it would still hurt like a bitch. _Damn this meatheaded piece of shit._

Senkuu started moving his hips in tandem with Tsukasa, trying to shove his dick as deep down the bastard's throat as possible. It only took three seconds of it before pain jolted up from between Senkuu's legs, drawing a muffled scream from his lips.

 _The bastard bit me._

A logical man would take the small victory he had and not anger further somebody who could kill him at any moment. But logic wouldn't help Senkuu much in this situation, he decided. So he kept pushing his hips up, and Tsukasa kept biting. Something in it was... exhilirating. The combination of pain and pleasure. Senkuu's body defied him, shuddering under Tsukasa's touch as his palm traveled up Senkuu's abdomen. Despite the head splitting headache, with every single movement, Senkuu felt himself inch closer to an orgasm he absolutely didn't want. Tears formed in the corners of his eyes, and he swore to himself it was because of Tsukasa's fingers, still pushing their way down his throat. He had no explanation for his toes curling up, and fingernails pushing their way into his palms.

With another bite, he shuddered more violently, and just when he swore he would come in a second, he was spared. Tsukasa's mouth retreated, and his fingers left Senkuu's mouth. He coughed a few times. He only got to take in one breath, before he was pulled up by his hair, Tsukasa's dick hard right before his face. 

"N-" He didn't get to say a word before Tsukasa shoved himself down his throat. He was big. Way thicker than a highschooler should be. Senkuu's eyes watered even more, tears running down his cheeks. Tsukasa fucked his mouth mercilessly with just his dry hand holding Senkuu in place by his hair. 

"Behave," he commanded. "If you bite me, I'll be forced to punish you."

The mush that his brain was deemed it a challenge. So he bit down, weakly, his teeth barely touching Tsukasa's skin. 

"Oh?" Tsukasa muttered, one eyebrow raised. He then shoved himself in harder, quicker, pushing Senkuu's mind to a limit.

So he bit down, falling for this obvious trap. With a hiss, Tsukasa stopped in his tracks, and instead of pulling Senkuu off by his hair, he bent back, his hand finding Senkuu's dick. He gave it a pump, then another one, and a wave of pleasure that overcame Senkuu made his jaw open just for a second. Which was enough.

Tsukasa pulled out, and let go of Senkuu's head. He stood up, looking down at Senkuu, likely admiring his handiwork. Even in the darkness of the cave, Senkuu could make out a smile on his face. 

He then kicked Senkuu's legs apart, and panic swallowed again. Tsukasa kneeled between Senkuu's thighs, pulling his legs up, and Senkuu tried to flail, fight, do _anything_ that could stop him. Logically, he knew there was no stopping at this point. But logic sat at the back of his brain, dulled with a headache and a wave of nausea. 

"Tsukasa..." He choked out. The man looked up at him with a ravenous smile. 

"Don't say I didn't warn you." Tsukasa growled. Senkuu then felt a pair of fingers prying his ass apart.

Saliva was definitely not enough. It hurt, stung like a hot iron was being shoved inside of him. A wail escaped his lips. He didn't want to give Tsukasa the satisfaction, but his body was way beyond his control. Relaxing his muscles was even harder, though he knew that was the one thing he could do to minimize the pain. Tsukasa's calloused fingers frantically slid in and out, working him open and tearing his entrance to shreds. He focused on breathing, but even that was difficult, with Tsukasa giving his dick an occassional stroke. 

Not even a minute passed before Tsukasa pulled his fingers out. Senkuu knew he was far from ready to take him in, and he knew even better that that was exactly what Tsukasa had wanted. He was worked up just enough for Tsukasa's dick to slide inside him, thick and long, and hot, and still somewhat slick with Senkuu's saliva. One push and the whole thing was in. He heard Tsukasa take a deep breath. Senkuu used that moment to do the same, but it wasn't enough to prepare him for when Tsukasa started moving.

Right off the bat, the tempo was insane. With each push, each of his own moans, Senkuu felt his mind go blank, neurons stopping their functions. At some point his moans must have bled into one continuous wail, because his own voice was all he could hear. Tsukasa's hands were placed firmly on Senkuu's hips, moving them as he moved, as if he was trying to hollow Senkuu out with his dick. Cold sweat dripped down Senkuu's back as he arched up off the ground, trying to at least not get his back scraped off by the floor of the cave. 

Tsukasa showed no sign of fatigue, pushing hard and fast, splitting Senkuu in two. And then, as Senkuu lifted his back, he hit the spot. With a moan that echoed throughout the cave, Senkuu came all over himself in waves. But Tsukasa wouldn't stop. He kept fucking Senkuu's brains out, his only reaction being a soft chuckle. He did move his hands up to Senkuu's waist though, his fingers digging into pale skin. Senkuu's mind, still tender from the orgasm, ravaged by Tsukasa's incessant movement, was full of curses. He was cursing Tsukasa, cursing his teenage body, cursing the idea to check out this stupid cave. He was way past the point of registering any sort of pain, so he could only guess at the damage being done to him. 

_Does this damn monster ever finish?_

Tsukasa bent over him, his face looming right over Senkuu's, and licked at his cheek. Licking off the tears, Senkuu realized. _Sick bastard_

An arm traveled under Senkuu's back, pulling him up, practically impaling him on Tsukasa's dick. He was now straddled in the man's lap, and his bound hands instinctively shot up, wrapping his arms around Tsukasa's neck for balance. 

"Move." Tsukasa commanded, his lips right by Senkuu's ear. "The faster you do it, the faster I'll come."

Senkuu bit his lips, trying to stop another wail from coming out. His aching throat did not listen. Neither did his legs, muscles now made of jelly. Still, more out of self-preservation than anything else, he tried to lift himself up. Only for his legs to give out completely, the fall pushing Tsukasa's dick deeper in and brushing against that sweet spot. Just that was enough to make him shiver, muscles spasming in preparation for another orgasm. He barely had enough strength to look down and see that his erection had indeed returned.

"Already out of steam, Senkuu?" Tsukasa whispered. "I suppose I'll need to help you out."

Before Senkuu could do anything to protest, Tsukasa grabbed his ass and started moving him, his own hips working in tandem. Senkuu's moans and wails resumed. In the midst of pain, Tsukasa hit the prostrate again, and Senkuu moaned in a voice he never thought he had. He could feel Tsukasa grin against his cheek. And then he could feel him bite at his ear, gentler than the bites he left up until now. Senkuu didn't know what to make of it, didn't feel like thinking about it at all. He was spent, exhausted with pain and nausea, and Tsukasa. He still managed to bend his arms, wrap them around Tsukasa's head, let his bound hands touch Tsukasa's hair. Managed to pull at it, but it didn't seem like Tsukasa cared. He simply moved to gnawing on Senkuu's still bleeding neck, leaving more bruises, more marks. 

He just wanted it to be over.

And soon it was. With all the stimulation, he came again, his body spasming. Immediately after, Tsukasa came inside of him. 

"Fucking... finally..." Senkuu breathed out, his voice barely audible. Tsukasa seemed to have heard him, and chuckled lightly against his neck.

When Tsukasa lifted him up and off of his dick, another, quieter moan left Senkuu's lips. Tsukasa kept smiling. But it was finally over. 

Senkuu was deposited back on the ground, feeling boneless and aching all over. Once he gathered some strength, he turned his head to see Tsukasa simply put his clothes back on. 

"I should probably kill you now." He said, his back to Senkuu.

Senkuu chuckled, barely breathing.

"Probably," he replied. He wouldn't even try to argue at this point. There was no strength left in him. If Tsukasa decided to choke the life out of him, he would simply allow him to. 

"The thing is," Tsukasa said, turning to face him. "I would miss you again."

"Oh, fuck off." Senkuu groaned. "Whatever you want... Just get on with it."

He still had to concentrate in order to breathe, and his body wouldn't listen to him. So when Tsukasa walked over to him, bent down, and planted a chaste kiss on his mouth, he simply let it happen.

Tsukasa then got right up and headed for the exit to the cave.

"I will come back for you, Senkuu." He smiled, and walked away. 

And Senkuu didn't know if it was meant to be a threat or a promise.


End file.
